Congenital (present from birth) deafness in dogs is a serious problem. Now, more than 80 breeds of dogs haven been know to be affected. In particular, two pigmentation have been associated with this form of deafness in dogs: the merle gene and the piebald gene. This type of deafness usually develops in the first few weeks after birth when pup's ear canal is still closed. The deafness is often due to degeneration of part of the blood supply to the cochlea.